Chelsea interim manager Rafael Benitez has admitted that he is unsure when John Terry will make a return from injury.

The Blues captain has been out of action with a serious knee problem since early November, but he was supposed to make his comeback against Sunderland on December 8.

"I talked with John on Wednesday morning and he is getting there and can start to do the warm-up with the team soon and then we will see how he will progress," The Mirror quotes Benitez as saying.

"Talking to the doctor, the problem is a build up of fluid on the bone. So at this stage we have no idea when he will be back."

Chelsea travel to Southampton in the third round of the FA Cup on Saturday.